Noise,not stimulus entropy,determines neural information rate

In the quest for deciphering the neural code, theoretical advances were made which allow for the determination of the information rate inherent in the spike trains of nerve cells. However, up to now, the dependence of the information rate on stimulus parameters has not been studied in any neuron in a systematic way. Here, I investigate the information carried by the spike trains of H1, a motion-sensitive visual interneuron of the blowfly (Calliphora vicina) using a moving grating as a stimulus. Stimulus parameters fall in two classes: those that have only a minor effect on the information rate like increasing the frequency bandwidth or the maximum amplitude of the stimulus velocity, and those which dramatically affect the neural information rate, like varying the spatial size or the contrast of the visual pattern being moved. It appears that, for a broad range of complex stimuli, the neuron covers the stimulus with its whole response repertoire regardless of the stimulus entropy, with the information rate being limited by the noise of the stimulus and the neural hardware.     

How Precisely Do Bonobos (Pan paniscus) Grasp Small Objects?

The general objective of this study was to compare the precise grasping behavior and intermanual differences in performance between three Pan paniscus and five Homo sapiens in grasping small objects. We compared the temporal pattern of two submovements of consecutive grasping cycles, the (visuomotor) reaching and the (sensorimotor) grasping. Both species were similarly successful in this task, they showed a behavioral right-hand preference and preferred specific types of grips. Bonobos required less time for reaching an object but a much longer time to grasp it than humans did. Thus, the species pursued different strategies. We assumed that this might be due to the different grip techniques. However, grip preferences did not serve a quicker intramanual performance but they pronounced differences between hands. Intermanual differences in timing were restricted to the reaching part and more strongly in bonobos than in humans. However, the right hand need not necessarily perform quicker. As in the case of humans, we assume that attentional cues were focused more on preparing a proper grip with the right hand than on a quick performance. However, strong intermanual differences in bonobos may indicate an overall stronger neuronal asymmetry in the motor organization of the finger musculature that prepare a proper grip than is true of humans.     

The neglected tool in the Bayesian ecologist's shed: a case study testing informative priors' effect on model accuracy

Despite benefits for precision, ecologists rarely use informative priors. One reason that ecologists may prefer vague priors is the perception that informative priors reduce accuracy. To date, no ecological study has empirically evaluated data‐derived informative priors' effects on precision and accuracy. To determine the impacts of priors, we evaluated mortality models for tree species using data from a forest dynamics plot in Thailand. Half the models used vague priors, and the remaining half had informative priors. We found precision was greater when using informative priors, but effects on accuracy were more variable. In some cases, prior information improved accuracy, while in others, it was reduced. On average, models with informative priors were no more or less accurate than models without. Our analyses provide a detailed case study on the simultaneous effect of prior information on precision and accuracy and demonstrate that when priors are specified appropriately, they lead to greater precision without systematically reducing model accuracy.     

Cell-free synthesis of membrane proteins: Tailored cell models out of microsomes

Incorporation of proteins in biomimetic giant unilamellar vesicles (GUVs) is one of the hallmarks towards cell models in which we strive to obtain a better mechanistic understanding of the manifold cellular processes. The reconstruction of transmembrane proteins, like receptors or channels, into GUVs is a special challenge. This procedure is essential to make these proteins accessible to further functional investigation. Here we describe a strategy combining two approaches: cell-free eukaryotic protein expression for protein integration and GUV formation to prepare biomimetic cell models. The cell-free protein expression system in this study is based on insect lysates, which provide endoplasmic reticulum derived vesicles named microsomes. It enables signal-induced translocation and posttranslational modification of de novo synthesized membrane proteins. Combining these microsomes with synthetic lipids within the electroswelling process allowed for the rapid generation of giant proteo-liposomes of up to 50 μm in diameter. We incorporated various fluorescent protein-labeled membrane proteins into GUVs (the prenylated membrane anchor CAAX, the heparin-binding epithelial growth factor like factor Hb-EGF, the endothelin receptor ETB, the chemokine receptor CXCR4) and thus presented insect microsomes as functional modules for proteo-GUV formation. Single-molecule fluorescence microscopy was applied to detect and further characterize the proteins in the GUV membrane. To extend the options in the tailoring cell models toolbox, we synthesized two different membrane proteins sequentially in the same microsome. Additionally, we introduced biotinylated lipids to specifically immobilize proteo-GUVs on streptavidin-coated surfaces. We envision this achievement as an important first step toward systematic protein studies on technical surfaces.     

Geostatistical characterization of the spatial distribution of Grapholita molesta and Anarsia lineatella males in an agricultural landscape

Abstract:  The results obtained in spatial analysis of pheromone trap catches of oriental fruit moth, Grapholita molesta (Busck) and Peach twig borer, Anarsia lineatella (Zeller), are reported. The studies were performed in the Molise region, central Italy, during 2002 and 2003. Local distributions of oriental fruit moth and peach twig borer males were considered in a heterogeneous landscape. The aim of the study was to determine the temporal and spatial variation in distribution and abundance of the insect pests inside small plots of fruit orchards (apple, kiwi, peach, pear and plum fruits) and outside (in field crops, irrigation channels, hedgerows and a river), and to evaluate the importance of the host plants in relation to the adult distributions. Results showed that the main 'hot spot' for both lepidopterous pests was in a stone fruit orchard in the northern zone of the study area; other infested areas were in stone orchards and, in the case of A. lineatella , also in plum orchards. The river seems to act as a barrier rather than an ecological corridor. The observed spatio-temporal distributions of G. molesta and A. lineatella differed and were determined mainly by the location of the most important host plants and by the tendency of males to move in the environment, i.e. inside and outside the breeding and mating sites. Adequate knowledge of these spatial processes should be considered as an essential prerequisite for integrated pest management programmes in a precision farming approach.     

Root foraging traits and competitive ability in heterogeneous soils

The responses of plant roots to nutrient patches in soil may be an important component of competitive ability. In particular, the scale, precision, and rate of foraging for patchy soil resources may influence competitive ability in heterogeneous soils. In a target–neighbor experiment in the field, per-individual and per-gram competitive effects were measured for six old-field species with known root foraging scale, precision, and rate. The presence and number of nutrient patches were also manipulated in a full factorial design. Number and presence of patches did not influence the outcome of competition. Competitive ability was not related to total plant size, growth rate, or root:shoot allocation, or to root foraging precision. Per-individual competitive effects were marginally correlated with root foraging scale (biomass of roots) and root foraging rate (time required to reach a patch). Therefore, competitive ability was more closely related to ability to quickly fill a soil volume with roots than to ability to preempt resource-rich patches.     

依托六大平台 实施医疗质量与安全精准化监管

运用信息化手段实施精准化的医疗质量与安全监管正在被越来越多的医院管理者所重视和接受。通过建立授权管理平台、环节质控平台、指标监测平台、医疗安全管理平台、电子病历质控平台和信息交互平台,对临床信息进行收集、统计、分析,为医院决策和医疗管理提供数据支撑,并及时反馈应用到临床医疗服务中,形成戴明环（PDCA循环）管理机制,切实打造医疗质量和安全精准化监管系统。     

Positional Information,Positional Error,and Readout Precision in Morphogenesis: A Mathematical Framework

The concept of positional information is central to our understanding of how cells determine their location in a multicellular structure and thereby their developmental fates. Nevertheless, positional information has neither been defined mathematically nor quantified in a principled way. Here we provide an information-theoretic definition in the context of developmental gene expression patterns and examine the features of expression patterns that affect positional information quantitatively. We connect positional information with the concept of positional error and develop tools to directly measure information and error from experimental data. We illustrate our framework for the case of gap gene expression patterns in the early Drosophila embryo and show how information that is distributed among only four genes is sufficient to determine developmental fates with nearly single-cell resolution. Our approach can be generalized to a variety of different model systems; procedures and examples are discussed in detail.